disable kernel build waring

hc

2024-05-10 093a6c67005148ae32a5c9e4553491b9f5c2457b

 kernel/samples/kobject/Makefile
..
..
@@ -1 +1,2 @@
1
+# SPDX-License-Identifier: GPL-2.0-only
1
2
 obj-$(CONFIG_SAMPLE_KOBJECT) += kobject-example.o kset-example.o